x402 finder: search paid APIs, ranked and live-checked API

Search and discovery of paid x402 API endpoints for a plain-language need, across Ultravioleta DAO x402 Bazaar and 402 Index directories. Dedupes by resource URL; ranks by relevance, verification, uptime, price and recency. Each result: resource URL, short description, USDC price, CAIP-2 networks, sources, verification. The top 3 GET endpoints get a live unpaid check: valid x402 402, live price, networks, canonical USDC, risk flags, OFAC SDN payTo screen, RDAP domain age.

$0.01 per call USDC over x402 v2 on Base, Polygon, Arbitrum, Avalanche or Sei. No signup, no API key. Requests that fail or match nothing are not charged.

Endpoint

GET https://api.kit-rx.com/v1/x402/find

Parameters

Name	Type	Required	Description
`q`	string	yes	What the agent needs, in plain words, 2-120 characters (e.g. weather forecast for a US city, token price, web page to markdown). e.g. `weather forecast`
`max_price`	string	no	Highest acceptable price per call in USD as a decimal, e.g. 0.01. Listings without a USDC price are left out when set. e.g. `0.01`
`network`	string: base, polygon, arbitrum, avalanche, sei, solana	no	Only endpoints that accept canonical USDC on this network.
`limit`	integer	no	Number of results, 1-10 (default 5). e.g. `3`

Example request

https://api.kit-rx.com/v1/x402/find?q=weather+forecast&max_price=0.01&limit=3

Without payment the server answers 402 Payment Required with the price (10000 atomic USDC) in the PAYMENT-REQUIRED header. Any x402 v2 client pays and retries automatically. A request with no parameters runs this example.

curl -i "https://api.kit-rx.com/v1/x402/find?q=weather+forecast&max_price=0.01&limit=3"

Pay from an agent

AgentCash: fetch the URL. OpenDexter MCP: x402_fetch. Kit Rx MCP server: https://api.kit-rx.com/mcp. Code:

import { x402Client } from "@x402/core/client";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { wrapFetchWithPayment } from "@x402/fetch";
import { privateKeyToAccount } from "viem/accounts";

const client = new x402Client();
registerExactEvmScheme(client, { signer: privateKeyToAccount(process.env.BUYER_KEY) });
const pay = wrapFetchWithPayment(fetch, client);
const res = await pay("https://api.kit-rx.com/v1/x402/find?q=weather+forecast&max_price=0.01&limit=3");
console.log(await res.json());

Example response

{
  "query": {
    "q": "weather forecast",
    "max_price": "0.01",
    "limit": 3
  },
  "result": {
    "results": [
      {
        "rank": 1,
        "resource": "https://verify-oracle.run402.com/api/weather",
        "title": "VerifyOracle",
        "provider": null,
        "description": "Live weather forecast and current temperature in Fahrenheit and Celsius with precipitation and wind from Open-Meteo and NWS (default New York).",
        "method": "GET",
        "price_usd": "0.001",
        "networks": [
          "eip155:8453"
        ],
        "sources": [
          "ultravioleta"
        ],
        "verification": {
          "status": "verified",
          "ultravioleta": {
            "health": "alive",
            "verified_by": "x402_challenge",
            "verified_at": "2026-11-13T00:36:14.000Z",
            "uptime_pct": 100,
            "tier": "verified",
            "calls_30d": 0,
            "unique_payers_30d": 0
          }
        },
        "score": 0.964,
        "live_check": {
          "checked": true,
          "verdict": "pass",
          "http_status": 402,
          "latency_ms": 221,
          "is_x402": true,
          "x402_version": 2,
          "challenge_valid": true,
          "price_usd": {
            "min": "0.001",
            "max": "0.001"
          },
          "networks": [
            "eip155:8453"
          ],
          "canonical_usdc": true,
          "ofac_sdn_match": false,
          "risk_flags": [],
          "problems": [],
          "domain": {
            "registrable": "run402.com",
            "platform": null,
            "age_days": 261,
            "rdap": "found"
          }
        }
      },
      {
        "rank": 2,
        "resource": "https://quantagentshop.com/v1/weather",
        "title": "Quant Agent Shop",
        "provider": null,
        "description": "Weather forecast for coordinates or a city name: current temperature, humidity, wind …",
        "method": "POST",
        "price_usd": "0.0013",
        "networks": [
          "eip155:8453"
        ],
        "sources": [
          "ultravioleta"
        ],
        "verification": {
          "status": "verified"
        },
        "score": 0.941,
        "live_check": {
          "checked": false,
          "verdict": null,
          "reason": "Not checked: the listing declares POST; the live check sends an unpaid GET only."
        }
      }
    ],
    "counts": {
      "ultravioleta": {
        "status": "ok",
        "returned": 14,
        "matched": 10
      },
      "402index": {
        "status": "ok",
        "returned": 20,
        "matched": 19
      },
      "merged": 34,
      "dropped": {
        "below_relevance": 4,
        "over_max_price": 0,
        "network_mismatch": 0,
        "reported_down": 1
      },
      "after_filters": 29,
      "returned": 3,
      "live_checked": 2
    }
  },
  "sources": [
    {
      "name": "Ultravioleta DAO x402 Bazaar (discovery API)",
      "url": "https://facilitator.ultravioletadao.xyz/discovery/resources"
    },
    {
      "name": "402 Index public API (402index.io)",
      "url": "https://402index.io/api/v1/services"
    }
  ],
  "generated_at": "2026-11-15T00:39:59.536Z"
}

Kit Rx: Pay-per-call data and safety tools for AI agents, paid in USDC over x402. No signup, no API key. Machine-readable: OpenAPI, llms.txt, /.well-known/x402, agent skills.